In conventional brush cutting technology, the boom of a standard brush cutting machine is located either to the side or the front of the cutting machine. A standard boom consists of two booms which appear as two arms of one boom. The first arm is located closest to the cutting machine and is fixedly attached thereto. The second arm is attached to the first arm and is called the dipper boom. In prior art blade assemblies for a brush cutting machine the blade is positioned at the distal end of the dipper boom. A conventional blade assembly is covered by a sheath which has an opening on its forward facing side. As the blades rotate the brush in front of the opening is cut. If the boom is turned the opening in the sheath moves, thus the blades opening would move away from the brush to be cut thereby cutting a narrower area. If the boom was rotated 90 degrees forwardly, the opening in the sheath would move such that the side of the sheath would replace the opening and the opening would move completely away from the brush and there would be no brush cut. In the prior art, the blade therefore can only be positioned at the side of the machine when cutting brush. So, in order to position the blade so that it is forward facing into the material to be cut, the prior art requires the physical movement of the machine to move the blade so that it will be presented in a proper cutting position to cut brush. It can be seen that this is a very labor intensive operation requiring much maneuvering by the operator and considerable fuel consumption by the cutting machine with the required movement of the machine.
Further, in the prior art, with the blade assembly attached directly to the distal end of the dipper boom, the blade assembly is rigid and flat against a ground surface that is most often not flat. It can be seen therefore, that in the prior art as the blade assembly moves evenly across the brush and the uneven ground that there will be an uneven cut of the brush, higher where there are depressions in the ground and lower where there is a raised area in the ground. Also, as the conventional rigid blade assembly strikes raised earth or large rocks there will be an abrupt jolt to the blade assembly and consequently to the cutting machine and machine operator.
U.S. Pat. No. 3,824,674 to Inoyama et al discloses an automatic assembly control for controlling a positioning mechanism in response to signals representative of the displacement or deflection of an elastic coupling means.
U.S. Pat. No. 4,414,750 to DeFazio discloses a remote center compliance device having two plates with elements interposed between, each element being axially compressible and laterally deformable.
U.S. Pat. No. 4,848,757 to DeFazio discloses a remote center compliance device having two plates with coil springs interposed there between for providing rotational and translational compliance.